Type Of Switch (Part 1)

Published by Harmony August 21,2020

There are various classification standards for switches, and the following are common:


(1) According to network coverage

LAN switches and WAN switches.


(2) According to the transmission medium and transmission speed

Ethernet switches, Fast Ethernet switches, Gigabit Ethernet switches, 10 Gigabit Ethernet switches, ATM switches, FDDI switches, and Token Ring switches.


(3) According to the switch application network hierarchy Enterprise-class switches, campus network switches, department-level switches and workgroup switches, and desk-type switches.


(4) According to the switch port structure Fixed port switches and modular switches.


(5) According to the working agreement layer Layer 2 switches, Layer 3 switches, and Layer 4 switches.


(6) According to whether it supports the network management function division Managed switches and non-network managed switches.


Because of the many advantages of the switch, its application and development speed is much higher than that of the hub. Various types of switches have emerged, mainly to meet the needs of various application environments. This article will introduce some mainstream classifications of current switches.


First, from the network coverage


1. WAN switch


WAN switches are mainly used in wide area networks such as telecommunications metropolitan area network interconnection and Internet access, providing a basic platform for communication.


2, LAN switch


This kind of switch is our common switch, and it is also the focus of our study. LAN switches are used in local area networks to connect terminal devices, such as servers, workstations, hubs, routers, network printers, etc., to provide high-speed independent communication channels.


In fact, in the LAN switch can be divided into a number of different types of switches. The following continues to introduce the main classification standards of LAN switches. Second, according to the transmission medium and transmission speed According to the network transmission medium and transmission speed used by the switch, we can generally divide the LAN switch into Ethernet switch, Fast Ethernet switch, Gigabit (G-bit) Ethernet switch, 10 Gigabit (10G bit) Ethernet switch, FDDI switches, ATM switches, and Token Ring switches.


1, Ethernet switch


The first point to note is that the "Ethernet Switch" referred to here refers to the Ethernet switch used for bandwidths below 100 Mbps. In fact, we will also talk about a "Fast Ethernet Switch" and "Gigabit Ethernet". "Switches" and "10 Gigabit Ethernet switches" are actually Ethernet switches, but they use different protocol standards or transmission media. Of course, the interface format may be different.


Ethernet switches are the most common and cheap, and their grades are relatively complete, and the application fields are also very extensive. They can be seen in large and small LANs. Ethernet includes three network interfaces: RJ-45, BNC, and AUI. The transmission media used are: twisted pair, thin coaxial cable, and thick coaxial cable. Do not think that Ethernet is RJ-45 interface, but the twisted pair RJ-45 interface is very common in network equipment. Of course, today's switches are usually not all BNC or AUI interfaces, because the current network using coaxial cable as the transmission medium is now rare, and generally based on the RJ-45 interface in order to balance the coaxial cable media. Network connection with BNC or AUI interface.


The Layer 2 switch is defined by the second protocol layer corresponding to OSI/RM because it can only work in the second layer of the OSI/RM Open Architecture model - the data link layer. Layer 2 switches rely on information in the link layer (such as MAC address) to complete wire-speed switching between different port data, and are generally applied to the desktop level of small enterprise or medium-sized enterprise networks.


The third layer is also defined by the network layer corresponding to the third layer of the OSI/RM open architecture model, which means that this type of switch can work at the network layer, which is more upscale and more powerful than the second layer switch. Because the Layer 3 switch works in the network layer of the OSI/RM model, it has a routing function, which provides IP address information to the network path selection and realizes wire-speed switching of data between different network segments. When the network size is large, it can be divided into small-faceted independent VLAN network segments according to specific application requirements to reduce the impact caused by broadcast. Usually such switches are modular in structure to accommodate flexible configurations.